With the ongoing increase of demands for wireless services, various services, such as data services, audio/video services, and mobile blogging, have emerged, which raise higher demand for the efficiency of data transmission, that is, the effectiveness of data transmission. Meanwhile, the convergence trend between the mobile communication network and the Internet has also gained much attention.
In the future wireless Internet applications, it is increasingly possible that a terminal acts as a service source and the demand for uplink transmission resource also further increases. However, as the wireless spectrum resources are scarce, if the operators choose to use more spectrum resources, the operating cost increases. If a higher order modulation mode is adopted to increase the transmission amount of the communication data, a higher signal-to-noise ratio is required, resulting in that a base station and a terminal require higher transmission power, which increases the energy consumption and adversely affects the green communication. At present, how to increase the effectiveness of air interface transmission already becomes one of the key factors that constrain the development scale of the wireless service.
When data services are borne wirelessly, a protocol stack header in a in a data packet occupies a substantial part of resources, while this part of resources actually are not effective data required for applications of users. FIG. 1 is a schematic structural diagram of a protocol stack of an RTP video service borne in a wireless network. For example, for one IPv6 voice communication group, a group payload that a user actually needs usually only occupies 22% of the whole group and the rest large part is the data protocol header information. The header information of a protocol data packet that is transmitted over a wireless air interface has to be reduced, to enhance the effectiveness of air interface transmission.
Multiple header compression mechanisms are provided in the prior art to reduce the header information of a protocol data packet that is transmitted over a wireless air interface. For example, the Robust Header Compression (Robust Header Compression, ROHC) mechanism provides a header compression mechanism applicable to a link having a high bit error rate and a long time delay. The ROHC mechanism is a flow-based header compression solution. In the ROHC mechanism, a reference group is taken from a certain flow, and for other groups, only the information that changes relative to the reference group in the header field is sent, to achieve the objective of compression, thereby saving the group header overhead and utilizing the bandwidth more effectively. Meanwhile, the ROHC mechanism also ensures that the ROHC mechanism has high effectiveness and reasonable robustness through the control of frequency and quantity of feedback messages, detection of asynchronous logic and error checking.
During the implementation of the present invention, the inventors find that the prior art at least has the following problems.
The existing header compression mechanism is targeted for the IP/UDP(/TCP)/RTP and mainly compresses protocol header information at different layers based on the concept of layer division. Such a compression mechanism does not consider the data redundancy among layers, especially, the data redundancy between other layers and the application layer, so the compression effect is very limited. Also, the compression mechanism is designed for wired networks and fails to consider the characteristics of wireless networks. When this compression mechanism is used in a wireless network to enhance the efficiency of the air interface transmission, the expected effect cannot be achieved and demands of users cannot be satisfied.